This data set contains the physiological data of Wilson's Storm-petrel (Oceanites oceanicus, https://www.marinespecies.org/aphia.php?p=taxdetails&id=137190) chicks at a breeding colony on King George Island (Islas 25 de Mayo, Antarctica), close to the Argentinian Base Carlini (62°14′S, 58°40′W; formerly called Base Jubany). Data was collected during three breeding seasons (2015 – 2017) to study influence of body temperature on developmental parameters. Age was determined by tarsus length following Quillfeldt & Peter (2000, doi:10.1007/s003000000158). During regular nest checks starting five days after estimated hatching date, body temperature and weight were measured daily, tarsus and wing length were determined every three days. Blood samples of maximum 70 μl were taken from the wing vein using 24 G single use hypodermic needles (Sterican© Braun), and disposable heparinized micro-haematocrit capillaries (Hirschmann®). The first blood sample was taken when chicks were at least nine days old and reached a body weight of 25 g. Following samples were taken weekly. Phytohemagglutinin assays were conducted in chicks aged 48 to 52 days. The sex of chicks was determined by molecular analysis based on blood samples dried on FTA ® (WhatmanTM) classic cards following Griffiths et al. (1998). Detailed descriptions of laboratory protocols can be found in Kuepper et al. (in prep).